How To Make A 1-Port Cable Loss Measurement - Keysight N9912A User Manual

CAT (Cable and Antenna Test) Mode
1-Port Cable Loss Measurements
A 2-port Insertion Loss measurement is usually more accurate than a 1-port
Cable Loss measurement. However, to perform a 2-port Insertion Loss
measurement, both ends of the cable must be connected to the FieldFox, and
the FieldFox must have option 110 installed.
In high-loss conditions, a Cable Loss measurement becomes 'noisy' as the
test signal becomes indistinguishable in the FieldFox noise floor. This can
occur when measuring a very long cable and using relatively high
measurement frequencies. To help with this condition, use High Power
page 3-9
(

How to make a 1-port Cable Loss Measurement

1. Press Preset then Preset..
2. Then
3. Connect the cable to be tested.
4. Press Freq/Dist and enter
measurement.
5. Press Sweep 3 then
trace is visible on the screen. The amount of time that is required increases
with longer cable lengths. Learn more in the Supplemental Online Help:
http://na.support.keysight.com/fieldfox/help/SupHelp/FieldFox.htm
6. Remove the cable to be tested.
7. Press Cal 5, then
8. Follow the prompts to perform calibration at the end of the jumper cable
or adapter. Learn more about Calibration in
CAT, and VVM Modes", on page
9. Connect the cable to be tested.
Low-level standing waves (also known as 'ripple') which may be visible in
reflection measurements, can hide the actual loss of the cable. Steps 10
through 13 can minimize the ripple. Perform the measurement with and
without steps 10 through 13 and choose the method with the least amount
of ripple.
10.Connect a LOAD at the end of the cable to be tested. This limits the
reflections to faults that are located in the cable under test.
11.Press Trace 6 then
into Memory.
12.Remove the LOAD and leave the end of the cable to be tested open.
Keysight N9912-90001 User's Guide
and Averaging page 3-6
) (
More then Cable Loss
Start
Min Swp
QuickCal or OSL.
Math and Memory
).
(1-Port).
and Stop frequency values of the
Time. Increase the Sweep Time until a stable
Chapter 7, "Calibration for NA,
7-1.
then Data->Mem to store the trace
3- 13